The field of the present invention is sunshields and, more particularly, portable sunshields for automobile windows to protect the interior of the automobile from the sun's rays while the automobile is parked.
Various sunshield devices are known in the art, including ones designed for positioning on the interior of an automobile windshield, as well as ones designed for exterior applications. For example, known interior shields include: a folding cardboard shade, such as that shown in U.S. Pat. No. 4,202,396; a fan-like venetian blind, such as that shown in U.S. Pat. No. 4,332,414; or even collapsible, fabric covered loops, such as that shown in U.S. Pat. No. 4,815,784.
In each instance, a balance must be struck between ease and flexibility of use, quality of protection provided, ease of storage, and unit cost. However, achieving this balance has proved somewhat elusive in the known art. For example, a folding cardboard shade is inexpensive and easy to store, but it provides mediocre insulation and has poor reflective qualities. Further, cardboard is not very flexible, e.g., it will permanently deform when folded or bent, and it tends to return to a folded shape. Also, cardboard is not suitable for exterior uses exposed to the elements. Fan-like venetian blinds are more expensive, require semi-permanent mounting and are also relegated to interior use. Their operation and storage is more cumbersome than is for a cardboard shade. Collapsible loops are awkward to assemble and dissemble and a fabric type material typically has inferior insulating and reflective qualities.
Ideally, a sunshield will be highly flexible for ease in positioning and storage; lightweight, durable, easy to clean and, perhaps, useful for other functions. Further, the shield should be made of materials having superior insulating and reflective properties to achieve superior sun blockage.